Method and means of perforating pipe



Nov. 18, 1941. A. L. ARMENTROUT y 2,253,412

METHOD AND MEANS 0F PERFORATING PIPE Filed Sept. 30, 1940 3 Sheets-Sheet 1 WMM A. L. ARMENTROUT METHOD AND MEANS oF PERFORMING PIRE Filed Sept. 30', i940 Nov. 1s, 1941.

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sheets-sheet 2 f l Figo-l 6L wwf/Vm@ Amm/moar Arrow/ fr Nov. 18, 1941.A A. L. ARMENTROUT METHOD AND MEANS F PERFORATING PIPE Filed sept. so, 1940 :s sheets-sheet 3 YPaten-ted Nov. 18, 1941 UNITED .STATES PATE NT OFFICE 2.108.412 lll'llUDANn-llm 0l' PIIIDIATINQ' Applieatianloptenkltlllhhllal" ilChins. 11M-0.2)

Thisinvention relatestooiieldequipment Plgurelisaviewshowingtheperioratinggun andparticularlypertainstoamethodandmeans supportediromadrill of perforting pipe, m. 2 Il In mlli'led 'le' 1n 10mm lec- Inconnectionwithvthedevelopmentoioil tionlhowingtheupperendofthepertorating welisandthelikeandinplacingthemonpro- 5 limandindicatingthetrlpmechanlsmactuated ductionitiscommonpracticetoutiiiseaperfrolnthetopoithewell. ioratedstringofpipeorscreencaaingthrough l'lisanenlargedviewinoentnisection which the cognate fluid from the iormationmay showingtheoperating solenoidand the'valve elenowandafterwhichtheiiuidmayheelevatedto mentallociatedtherewith., the surface. In some instances the perforated l0 Fig. 4 is a fragmentary view in longitudinal pipe prcaaingispertqrated abovelroundand sectionlhowingtheplungerltruct thereafter lowered into the hole. These pertorations are usually undercut so that the openingoitheperiorationswillhelargerontheinsideoithecasingianitisontheoutaideotthe casing. Due to this arrangement silt and other materialisscreenedoutotthe peri'orationaand the periorations are furthermore kept clear lince pose which punch or'eut holea through or the casing. Periorating guns have provided i'orriorcing a projectile wall of the casingand other means, abrasive fluid Jetsrhave been used in ingthecasingwalla Itistheprinciple the presentinventionrtopruvide oi' having 'a larger opening along the innersuriaoe'oi thewallthan it does at the outer surface, thereby producing l a desirable undercut perforation.

ure

Pig.5isaviewinfrlmentary|ectionahowing the means 1for electing the peri'orating electrode casing.

enlarged fragmentary view showing structure disclosed in Fig. 5, indithe electing members in elevation.

is a view transverse section through as leen on the line I-1 'ings previously described 21 derstood that all of the various sleeves and haus. are assembled together complete enclosure for and that they form the which the present the periorating structure with invention is concerned.

Brieily considered. the principal operation o! this invention is to provide electrodes which are projected outwardly into contact with a circum scribing piece oi pipe and which electrodes are moved gradually by the action of a solenoid, the movement of which is hydraulically controlled and checked so that the electrode will be fedl slowly outwardly from the body o! the housing and to a contacting and perforating position with relation to the casing.

Referring particularly to Fig. 2. it will be seen that the upper pin end 3l oi the sub is internally threaded to receive a bushing 8|. The

bushing 3| is formed with a counterbore 82 which terminates in a-central bore 33. Reciprocating through the counterbore and the central bore 33 is a trip pin 34. This pin is formed at its upper end with an enlarged head 35 vwhich is presented to the opposite lower end of the central bore 88 of the tubular supporting element l0. The lower end oi the pin is threaded, as indicated at 31, and projects below the lowerend of the bushing 8| andinto a sleeve 38. The threaded end of the pin 34 engages the bore of a contact plunger 38. This plunger is made of dielectric material and supports a metal contact ring 48 adjacent to its end and when moved downwardly will engage spring contact fingers 4| and 42 which are included within an electric circuit to be hereinafter described. 'I'he spring contact nngers are formed as a part of a tubular member tting within the lower end of the sleeve 38 and being held downwardly by engagement of the end of the sleeve with a flange 43. The ange 48 rests against an insulating washer 44 which occurs at the bottom ofthe bore 45 within which the sleeve 38 is seated.

The pin 34 is designed to be forced to its lower position by the dropping of an instrument through the pipe I0. These instruments are designated in the trade as go-devils (24'), and are heavy bars of metal of sufficient weight to force the pin 34 downwardly when the bar strikes the head 35. In order to hold the pin in its innermost position after it has been thus struck a spring bushing 48 is provided having spring iingers 41 which extend inwardly around the shoulder on the head when the pin is in its uppermost position, and which flex overthe end of the pin when the pin is in its lowermost position, whereby the pin will be locked in its lowermost position. The purpose of this pin is to insure that electric circuits to be completed within the apparatus are not completed until the operator so desires, thus avoiding accidental operation of the tool. As a continuation sub is a central restricted circulation bore 48 'which extends downwardly to communicate with the compartment within the battery casing I3. An insulation washer 48 is disposed at the lower end of the pin I2 of the sub and lies over the top of a series of batteries 50 which furnish electrical energy for the solenoid as well as electrical energy for the electrode. f

Referring particularly to Fig. 3 of the drawings, it will be seen that the solenoid valve housing |4 is formed at its upper end with acentral bore This bore is formed with a threaded counterbore 52 at its upper end into which a of the bore 45 Within thev means solenoid unit Ily is secured. This solenoid unit comprises a central spool-shaped core 54 around which a magnetic coil Il is arranged. A D

Vrestricted orifice bushings between the coil and the side of the bore is an insulating covering tral cylindrical 'bore 51 through it and within which bore a solenoid pin Il reciprocates. The

pin extends downwardly below the core 54 and terminates in a conical point 88 at its end. A collar 8| is formed on the pin to limit the upward movement of the pin into the core of the solenoid. The downwardly extending portion oi the pin passes into a sleeve 82 which has a partition wall ll at a point intermediate its length. Resting upon this partition wall and exerting a force against the -collar 8| is a spring 84 which tends to hold the pin upwardly against the action of the solenoid. The sleeve 82 rests against a shoulder at the lower end ofthe bore Il within which the sleeve threaded counterbore 88 which receives a threaded ring 1|l. The counterbore forms a shoulder adjacent vto the upper end of a central passageway 1|. The threaded ring 10 holds a breakable disc 12 over the end of the bore 1| and when the conical point 60 of the pin 58 moves downwardly it will penetrate and break the disc 12 so that an opening will be eil'ected to the bore 1|. Mounted in the lower end of the tubular plunger 88 is a tubular extension 13. This extension is threaded into the end of the plunger 88 and carries packing members 14 which .create a tight sliding t with the bore of a cylinder 15. A circulation passageway 16 extends downwardly into the tubular extension to a point below they packing member 14 and is provided with lateral outlet openings 11 which communicate with the cylinder 15. A cylinder plug 18 is threaded into the 'lower end of the member 15 and forms a packing for the lower end of the extension member 13. Formed in the wall of the plug 18 are 18 which control the outletl of fluid from the cylinder 15 and. cause the cylinder to have a dash-pot action `to control the movement of the plunger for a purpose to be hereinafter described. l

The lower end of Vthe plug 18 is internally threaded to receive a coupling 80. An extension of this coupling is threaded to receive a tube 8| within which a spring 82 is positioned. The upper end of the spring 82 rests against the lower end of the coupling. The lower end of the spring 8 2 rests against the head 83 of a plunger 84. The plunger 84 extends downwardly through a cap 85 carried at the lower end of the tube 8|. Carried upon the tube 8| near its lower end is a piston member 88 which has a sliding ilt with the internal bore 81 of the valve plunger housing I8. The lower end of the plunger 84 is conical as indicated at 88 and has a rounded point which projects through an opening 88in the upper end of the electrode housing 2| and rests upon an arcuate member 88 formed at the upper end of the electrode wedge 8|. The electrode wedge is formed `with an inclined face 82 and a straight back face 83. As shown in Fig. 6 of the drawings. pairs of these wedges 8| lare assembled with their inclined faces 82 disposed in opposite rections for separately actuating electrodes 84 which may be projected oppositely from the body of the housing 2|; The electrodes 84 are I8.' The core I4 has a cen- 82 fits. A reduced bore 481 extends downwardly within the valve chamand rests against a spring 99.

-which is associated with disposed in a plane at right angles to the longif tudinal axis of the housing 2| and project through packings 99 mounted in bores I9 in the side wall of the housing and secured by threaded nuts 91. As shown-in Fig. 54 of thev drawings, a shoulder 99 is formed on each of the wedges The spring 99 is disposed around a rod |99. The springs act to' hold the wedges 9| in their retracted position. 'I'he electrodes are supported by springs IUI which tend to hold the electrodes in their retracted positions. Disposed beneath the -electrode housing is the expanding core element 29 a spring basket acting to frictionally engage the side wall of thevv casing 29 so that when the perforated toolis in any desired set position the spring basket will tend to center the tool in the middleoi' the casing and insure that the electrodes will contact the casing with substantially equal pressure as the perforating operation proceeds.

In operation of the present invention the ydevice-is assembled as contact fingers 4| and conductors |92 and |93. A fuse |94 is placed in the line of the conductor |92. This conductor leads to one pole of the solenoid coil Il. The opposite pole of the solenoid coil I3 is connected by a conductor |03 to one of the batteries I9. The opPOSite pole of this particular battery` connects with the conductor |99. The batteries are in series. A wire |94 connects the positive with the negative of the batteries and a wire |99 connects the battery with the'member 19, which in turn is provided .with a wire |99 establishing connection with the electrodes 94. Attention is also called to the fact that the conductor ill is grounded to the housing i9 so that. a circuit will be completed between the casing 29 and the electrode 94 when the electrode is pushed outwardly from the body and into contact with the casing. It is to be understood that the various circuits are protected by suitable insulation so that there will not be any short circuits before the electrode actually contacts the casing.

When the structure is wired and assembled as shown in the drawings, it is then lowered into the 1101s. at the selected point for making perhere shown. The spring 42 are connected with' broken oil'. It is to forations the spring basket is manipulated so that it will seat and allow the slips 2l to move outwardly and engage the wall of the hole `to hold the structure tightly and to prevent it from moving longitudinally. The go-devil is thendropped through the string of pipe Il so that it 'will strike the head 2l of the pin 94. This will force the pin 94 downwardly against the action of the spring |91 until the head oiI the spring moves beneath the spring ilngers 41. These fingers will thenlock the head in its innermost position and will hold the contact ring 4I downwardly in a position of contact between the lingers 4| and 42; This will complete two circuits through the batteries Il. It will be understood that as ,many batteries may be provided as necessary for producing the desired electric current, although only two are shown in the drawings. After the go-devil has been dropped to move the pin Il downwardly one circuit established will energize the solenoid coil I9. When this coil is energized it will move the pin Il downwardly against the expansive action of spring 94. It will be understood that the spring hasbeenactingtoholdthepinllinitsuppermost position. When the pin I9 moves downwardly its conical point 99 will enter the opening in the ring 9| and break the diaphragm 12. When this takes places the circulating fluid will force its way downwardly through the tubular plunger 99 moving it downwardly against the expansion of spring-92, which will in turn force the plunger I4 downwardly. This movement is resisted and controlled by the escape of fluid from the restricted opening 'I9 in the plug 'I9 as the packing members 14 move downwardly, the result being that the action of the electrode is retarded so the extension member I3 is gradually forced downwardly as the fluid from the cylinder 1l is exhausted. As the member 94 moves downwardly it exerts a pressure upon the wedge members 9|. This forces the inclined wedge faces 92 against the inner ends of the electrodes 94 and gradually forces the electrodes out and into contact with the casing 29. Attention is directed to the fact that a spring 92 is interposed between the extension member 13 and the rod 94 so thatthe electrode will not be forced outwardly' by a positive mechanical action but 4in a manner to yieldably forcelthe electrode against the casing as it contacts therewith and creates an are which will burn a hole in the casing. Attention is directed to the fact that the arc will form a crater on the contacting side of the casing so that the perforation produced will be undercut-and will be of larger diameter within the casing than it is on the outside. y

By reference to Fig. 9 of the drawings the action of the electrode in perforating the casing is indicated. The duration of the electric circuit is controlled by the time fuse l|04. This fuse has been selected so that the electrode will have had suilicient time to burn a hole through the casing before the current iiow is interrupted. By the time the hole has been burned through the casing it may be that the point of the electrode or a portion of its length will be' burned away. It will not be dimcult, therefore, to withdraw the entire tool from the well without any retarding action from the electrode. In the event that the electrode is not burned away it may be be understood that while two electrodes are shown that any number of electrodes may be provided and operated simultaneously.

It will thus be seen that the method and means of perforating a casing here disclosed insures that a casing may be perforated with a uniform undercut hole with certainity of action and without possibility of splitting the casing as is now often done, and by means that are direct in operation and easily controlled.

While I have shownthe preferred method of performing my invention and a preferred apparatus for use in practising the same, it is to be understood that various changes might bemade in the steps oi' the method and the combination of parts of the apparatus by those skilled in the art without departing from the spirit of the v invention as shown.

be perforated, and

4 Y 2,263,412 V I 2. A well casing perforating device comprising a body member adapted to be positioned within a well casing, an electrode carried thereby, means for moving the electrode into contact with the well casing, an electric circuit for the electrode, 5

and means for controlling thesame whereby the electrode will burn a perforation through the casing.

3. A device as in claim 2, said controlling means including a timing element to controlthe l0 'within the unit, an electrode carried by the unit and adapted to move laterally to a point in contact with a casing to be perforated, means for moving the same, rand control means, the action of which is manipulated from a point remote "-20 from the unit to initiate actuation of the electrode and to establish an electric current therethrough.

5. A device as rupting the electric current in claim and means intermined time.

6. A device for perforating well casing and the like which lcomprises a perforating unit adapted to be positioned at a desired point within a well casing, a source of electricity included within the 'a unit, an electrode carried by the unit and adapted to move laterally to a point in contact with a casing to be perforated, means for moving the same, control means, the action of which is manipulated from a point remote from the unit :i5

to initiate actuation of the electrode and to establish. an electric current therethrough, and

lmeans acting to center the unit within the casing.

1. A perforating device adapted to be lowered i 'into a well casing wardly in a yperforating operation, and means 50 actuated by the dropping of a go-devil through the drill string forlinitiating operation of said feed means and establishing said circuit.

8. A device as in claim 'I and means acting to interrupt said circuit at the conclusion of a 55 perforating operation. A

9. A perforating device adapted to be lowered into a well casing to form perforations in the same, including a string of pipe, a perforating unit suspended at unit including an outer housing, electrodes laterally movable with relation to the housing to after a predeter- .25

to the housing to 45 the lower end thereof, said 6o contact the walls of a casin to be perforated, a source of electrical energy within the housing to .supply electric current to the electrodes, means for gradually feeding thef-electrodes outwardly in a perforating operation, means actuated by the dropping of a go-devil through the drill string for initiating operation of said feed means and establishing said circuit. and yieldable means disposed between the electrode and its operating means whereby the electrode will be yieldably fed against the casing.

10.. A perforating device adapted to be lowered into a well casing to form perforations in the same, including a string of pipe, a perforating unit suspended at' the\lower end thereof, said unit including an outer housing, electrodes laterally movable with relation to the housing to contact the wall of a casing to be perforated,

a source of electrical energy within the housing to supply electric current to the electrodes, means for gradually feeding the electrodes outwardly in a perforating operatiommeans actuated by the dropping of a go-devil through the drill string for initiating operation of said feed means and establishing said circuit, means acting to interrupt said circuit at the conclusion of a perforating operation, and means for disposing the perforating unit centrally of the casing and locking the same preparatory to the perforating operation.

11. A device for perforating well casing and the like comprising a string of pipe adapted to be lowered into a well, a perforating unit at vthe lower end thereof, said unit including a housing, laterally `movable electrodes carried thereby, a solenoid within the housing having a plunger moving to initiate an electrode feedingv action. and means between said plunger and the electrodes for transmitting motion of the plunger to the electrodes.

12. A device as in claim 1l, said last named means including a dash-pot acting to retard the plunger of the electrode and the resulting movement of the electrode.

13. A device for perforating well casing and the like comprising a string of pipe adapted to be lowered into a well, a perforating unit at the lower end thereof, said unit including a housing, laterally movable electrodes carried thereby, a solenoid :within the housing having a plunger moving to initiate an electrode feeding action, means between said plunger and the electrodes for transmitting motion of the plunger to the electrodes, said last named means including a dash-pot acting to 'retard the plunger of the electrodes and the resulting movement of the electrodes, and yieldable means interposed at a point between the plunger of the solenoid and the electrodes and through which the moving force of the plunger is transmitted to the electrodes. 

